The present invention relates to a multicolor writing instrument with an automatic return function, and more particularly, to a multicolor writing instrument that is more simply configured to cause an exposed nib of one of pen cores of the writing instrument to be automatically accommodated in a pen housing of the writing instrument when the writing instrument is put on clothes using a clip, thereby preventing the nib of pen core of the writing instrument and the clothes from being damaged when the writing instrument is not in use.
In general, each of pens for various purposes, including ballpoint pens, is comprised of a pen core and a spring in a housing, a knob and the like such that a nib of the pen core may be exposed to the outside while lifting or lowering the pen core in the housing.
In addition to such a monochrome pen, a multicolor writing instrument simultaneously having pen cores for various colors in a single housing has been widely used in recent years.
In order to expose a nib of one of a plurality of pen cores for different colors in the multicolor writing instrument, a knob is used to cause a nib of a pen core for a color desired by a user to be extracted in a slide manner when the user wants to take notes, thereby enabling writing.
The multicolor writing instrument is equipped with a plurality of pen cores 50 and springs for providing elastic forces required when the pen cores 50 are projected and retracted, in a limited space of a housing. An upper housing of a main body of the multicolor writing instrument is provided with respective knobs 60 connected to the pen cores 50 filled with multiple inks.
Each of the knobs 60 is slid under guidance of a relevant one of guide holes 21 of the upper housing 20 in a state where the knob is moved and locked, or released and returned. Upon movement of a selected pen core 50, a nib placed at a tip of the pen core is exposed to the outside of the writing instrument.
For example, a case where a user wants to use a pen core for blue will be described by way of example. In this case, the user downwardly slides a manipulation portion of a blue knob 60 connected to the pen core 50 for blue. Then, as a return spring 70 is compressed, the selected knob 60 and the pen core 50 are moved forward within the housing.
The knob 60 is slidably moved under the guidance of a relevant one of the guide holes 21 formed in a longitudinal direction of the upper housing 20 according to the orientations and number of the pen cores 50. At this time, the knob 60 moves downwardly and also slightly inwardly in the guide hole 21, and a top locking protrusion 61 formed at an uppermost portion of the knob is caught by locking steps 22 formed in the approximately middle of and inside the guide hole 21, so that a nib of the pen core 50 protrudes to the outside and thus a blue ballpoint pen is ready for writing.
Even when the user wants to use a pen core for another color, the writing instrument will be operated in the same manner as above. For example, when the user wants to use a pen core 50 for red in this state, a red knob 60 exposed to the outside of the upper housing 20 is pressed and moved downwardly and a lower unlocking portion 63 of inwardly protruding upper and lower unlocking portions 62 and 63 of the red knob is then brought into contact with and presses an upper unlocking portion 62 of the blue knob 60.
Therefore, the top locking protrusion 61 of the blue knob 60 which has been caught by the locking steps 22 is released, so that the blue knob 60 is returned to its original position by an elastic force of the return spring 70 which has been compressed. As the user further moves the red knob 60, a top locking protrusion 61 of the red knob 60 is caught by locking steps 22 formed in the approximately middle of and inside a relevant one of the guide holes 21, so that a nib of the pen core 50 for red protrudes to the outside and thus a red ballpoint pen is ready for writing.
In this manner, pen cores for two to five colors such as blue, red, black and the like are accommodated in a single pen housing, and the respective pen cores for desired colors can be selectively used as a multicolor writing instrument.
In order to cause a nib of a pen core, which has been exposed to the outside, to be accommodated in the housing while this multicolor writing instrument is stored or carried by a user, any of the other knobs 60 other than a knob corresponding to a pen core which has been already projected is manipulated to be moved to such an extent that a top locking protrusion 61 of the caught knob can be released from locking steps 22 and then the caught knob is returned to its original position, whereby all of the pen cores 50 and the knobs 60 return to a state before use of the multicolor writing instrument.
However, a conventional multicolor writing instrument has problems in that, for example, when it is put on a pocket of clothes or the like using a clip in a state where any of the nibs of the pen cores 50 is exposed to the outside of the housing, the exposed nib of the pen core 50 is damaged or the clothes are damaged by an ink due to contact of a nib of the pen core with the clothes for a long period of time, thereby often causing obstinate situations for users of the multicolor writing instrument.